Dishwasher

ABSTRACT

A hood type dishwasher ( 1 ) having a treatment chamber closeable by a hood ( 2 ), which can be moved in the vertical direction relative to a machine frame of the dishwasher ( 1 ), wherein, in the closed state of the treatment chamber, the treatment chamber is delimited by inner surfaces of the hood ( 2 ) and by at least one rear side wall region ( 4 ) of the machine, which is fixed to the machine frame of the dishwasher ( 1 ). The hood ( 2 ) includes a guide system for guiding the hood ( 2 ) as it moves relative to the machine frame. The guide system is of concealed design such that, at least in the open state of the treatment chamber, it is present in its entirety outside the region which, in the closed state of the treatment chamber, is defined by the inner surfaces of the hood ( 2 ) and the rear side wall region ( 4 ).

TECHNICAL FIELD

The invention relates, in general, to the field of commercial dishwashing. The invention relates, specifically, to dishwashers, in particular commercial dishwashers, which are designed in the form of box-type dishwashers.

BACKGROUND

Box-type dishwashers are dishwashers which can be loaded and unloaded manually. Account is taken here, in particular, of box-type dishwashers which are designed in the form of hood-type dishwashers.

A dishwasher which is designed in the form of a hood-type dishwasher usually has a treatment chamber for cleaning washware. It is usually the case that a wash tank is arranged beneath the treatment chamber, it being possible for liquid from the treatment chamber to flow back into said wash tank under the action of gravitational force. The wash tank contains wash liquid, which is usually water, to which detergent can be added if appropriate.

A dishwasher which is designed in the form of a hood-type dishwasher also has a wash system with a wash pump, a line system, which is connected to the wash pump, and with a multiplicity of spray nozzles, which are formed in at least one washing arm. The wash liquid located in the wash tank can be fed from the wash pump, via the line system, to the spray nozzles and can be sprayed, by way of the spray nozzles in the treatment chamber, onto the washware which is to be cleaned. The wash liquid sprayed then flows back into the wash tank.

The wash system is also usually assigned a screening system, in order for solid particles of dirt to be separated off from the wash liquid sprayed via the spray nozzles onto the washware which is to be cleaned. Such screening systems are designed preferably such that they can be removed manually from the dishwasher for example for cleaning purposes.

At the end of each working day, the dishwasher is, or has to be, cleaned. This involves a large number of working steps which have to be performed manually. For the purpose of cleaning for example a hood-type dishwasher, first of all the washing and rinsing arm of the wash system and also the screening system have to be removed. The screening system removed is then sprayed manually with hot water and in addition—depending on the degree of soiling—scrubbed manually.

In the case of the washing and rinsing arm which has been removed, first of all the cleaning end caps, which are usually arranged at the end of the washing and rinsing arms, are removed and then each individual wash tube of a wash arm has water flushed through it. Finally, the wash arm is cleaned in its entirety, i.e. it is sprayed and scrubbed manually. The rinsing arms are likewise sprayed with water and possibly scrubbed manually. Rinsing arms usually do not have cleaning end caps, since no dirt is expected to be found within the rinse tubes.

Once the treatment chamber of the dishwasher has been emptied in its entirety, the treatment chamber is sprayed with hot water and in some cases (if necessary) cleaned manually with a cleaning cloth and possibly with the aid of a detergent solution. Depending on the size of the machine, the entire operation to clean the interior of a hood-type dishwasher takes between 10 and 30 minutes, wherein the quantity of fresh water used for cleaning the machine is between 60 and 120 liters.

Once the interior of the hood-type dishwasher has been cleaned, and once the wash-system components which have previously been removed have been cleaned, the individual parts of the wash system have to be installed correctly in the treatment chamber of the dishwasher again.

SUMMARY

The invention is based on the object of specifying a dishwasher of the type mentioned in the introduction in the case of which the cleaning which has to be performed at the end of a working day can be rendered more efficient. In particular, the intention is to specify a dishwasher which is designed in the form of a hood-type dishwasher and in the case of which at least some of the working steps which are necessary for cleaning the interior of the dishwasher can be simplified, or even done away with altogether, in order thus to cut back on staff and, at the same time, to be able to reduce the resources (water, energy, chemicals) which are used for cleaning purposes.

The object on which the invention is based is achieved by the subject matter of independent patent claim 1, advantageous developments thereof being specified in the dependent claims.

Accordingly, the invention relates, in particular, to a commercial dishwasher which is designed in the form of a box-type dishwasher, wherein the dishwasher has a treatment chamber, in which washware, and in particular washware accommodated in racks, can be treated in accordance with a predefined or predefinable treatment program. In particular, provision is made, in the case of the dishwasher, so that the treatment chamber can be closed by a hood, which can be moved in particular in the vertical direction relative to a machine frame of the dishwasher, wherein, in the closed state of the treatment chamber, the treatment chamber is delimited by inner surfaces of the hood and by at least one wall region, in particular on the rear side of the machine, which is fixed to the machine frame of the dishwasher.

According to the invention, provision is made in particular for the hood to be assigned at least one guide system for guiding the hood as it moves relative to the machine frame and the in particular rear-side wall region, wherein the at least one guide system is of concealed design such that—at least in the open state of the treatment chamber—it is present in its entirety outside the region which, in the closed state of the treatment chamber, is defined by the inner surfaces of the hood and the in particular rear-side wall region.

The advantages which can be achieved by the solution according to the invention are obvious: the provision of a concealed guide system for guiding the hood as it moves relative to the machine frame avoids difficult-to-clean undercuts in particular on the rear-side wall region of the dishwasher, and therefore it is no longer necessary for the rear wall of the dishwasher to be cleaned manually, during the proceedings, in places which are difficult to access. Rather, the solution according to the invention allows the rear-side wall region to be designed in a flat state, without undercuts, since the rear-side wall region has no hood guide which is visible to staff.

In this way, when the interior is being cleaned in particular at the end of a working day, the rear-side wall region can be straightforwardly wiped off, in order thus to reduce the manual cleaning outlay for the rear wall of the machine to a minimum, to minimize the risk of injury to staff by getting rid of sheet-metal profiles, which usually, in the case of visible hood guides, have to be provided on the rear wall of the machine, and to reduce in particular the quantity of adhering residues of dirt to a minimum.

In other words, the dishwasher according to the invention no longer—as has been the case hitherto—has a hood guide which runs on both sides over the entire height of the rear wall of the machine; rather, it just has a guide in particular in the upper region of the rear wall of the machine, and said guide is no longer situated in a location which staff can see and clean.

The new positioning and configuration of the hood guide make it possible to realize, in particular, a flat and planar rear wall of the machine. Said rear wall can be cleaned in a considerably more time-saving manner, since fewer residues of dirt can adhere to it and the accessibility is significantly improved. Moreover, the existing machine dimensions and function of the dishwasher remain unchanged.

In order to be able to realize reliable guidance of the hood relative to the machine frame and the in particular rear-side wall region, the hood is assigned preferably at least two in particular lateral guide systems, which—in respect of the guide direction—are arranged in a parallel state, wherein said guide systems are of concealed design such that—at least in the open state of the treatment chamber—they are present in their entirety outside the region which, in the closed state of the treatment chamber, is defined by the inner surfaces of the hood and the in particular rear-side wall region.

In order to realize the hood guide, provision is preferably made for the at least one guide system to have at least one guide element and at least one guide rail, which interacts with the at least one guide element, wherein the at least one guide element is connected to the in particular rear-side wall region and the at least one guide rail is connected to the hood and, in particular, to an inner surface of the hood.

In this context, it is, in particular, conceivable for the at least one guide element to be provided in a region which, in the open state of the treatment chamber, is present between the in particular rear-side wall region and the hood and, in particular, between the in particular rear-side wall region and the inner surface of the hood, to which the at least one guide rail is connected.

This realization of the guide system has an in particular space-saving construction which is simple and easy to realize and allows the guide system to able to be of correspondingly concealed design.

Possible guide elements are rolling or roller bodies, in particular guide rollers, or sliding elements, in particular sliding blocks.

In this context, it is advantageous for the guide system to have at least two guide elements, which are arranged one behind the other in the guide direction, this permitting purely vertical guidance, whereas the other degrees of freedom of movement are blocked.

According to preferred embodiments, the hood of the dishwasher is designed in the form of a hood which can be moved vertically relative to the machine frame and relative to the in particular rear-side wall region. In the case of these embodiments, the at least one guide rail is designed, in particular, in the form of a vertically running guide rail.

In particular, in this context, it is recommended for the at least one guide rail to have a cross-sectional geometry which complements the at least one guide element, preferably an in particular C-shaped cross-sectional geometry, although, of course, other ways of realizing the guide rail and/or the corresponding guide element are also possible.

The solution according to the invention and, in particular, the concealed design of the guide system make it possible for the in particular rear-side wall region, which delimits the treatment chamber when the latter is in the closed state, to have an undercut-free and/or edge-free surface, which has a positive effect in respect of reduced soiling during operation of the dishwasher and also a positive effect in respect of cleaning of the interior being as straightforward and efficient as possible.

As an alternative to this, the situation where—with the exception of an in particular central and vertically running region of the in particular rear-side wall region—the in particular rear-side wall region, which delimits the treatment chamber when the latter is in the closed state, has an undercut-free and/or edge-free surface is conceivable. In the case of this embodiment, the vertically running central region of the in particular rear-side wall region can then serve to accommodate line systems for supplying the upper washing and/or rinsing nozzles.

In a development of the dishwasher according to the invention, provision is made for the dishwasher to have a wash tank, which is designed, and arranged, in relation to the treatment chamber of the dishwasher such that, when wash liquid and/or final rinse liquid are/is being sprayed in the treatment chamber, at least some of the liquid sprayed flows back into the wash tank under the action of gravitational force, wherein the in particular rear-side wall region merges continuously into a wall region and/or base region of the wash tank.

This configuration effectively reduces the risk of soiling and/or of particles of dirt accumulating during operation of the dishwasher. In addition to this, it is possible for the region, in particular the rear-side wall region, of the dishwasher, the transition region into the wash tank and the wash tank to be cleaned manually or automatically, as easily as possible, by spraying.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail hereinbelow on the basis of an exemplary embodiment and with reference to the accompanying drawings, in which:

FIG. 1 shows, schematically, a front view of a prior-art hood-type dishwasher in the open state;

FIG. 2 shows, schematically, a side view of the hood-type dishwasher according to FIG. 1;

FIG. 3 shows, schematically, an isometric detail-specific view of the hood-guide rail which is used for the hood-type dishwasher according to FIG. 1;

FIG. 4 shows, schematically, a front view of an exemplary embodiment of the dishwasher according to the invention in the open state;

FIG. 5 shows, schematically, an isometric view of the dishwasher according to FIG. 4;

FIG. 6 shows, schematically, a detail-specific view of the dishwasher according to FIG. 4;

FIG. 7 shows, schematically, an isometric view of an upper region of the rear wall of the dishwasher according to FIG. 4;

FIG. 8 shows, schematically, an isometric view of the guide rail on the hood of the dishwasher according to FIG. 4; and

FIG. 9 shows a side view of the detailed positioning of the running rollers of the guide system of the dishwasher according to FIG. 4.

DETAILED DESCRIPTION

The exemplary embodiment of the dishwasher according to the invention which is shown in the drawings is designed in the form of a hood-type dishwasher, which can be loaded with a rack, and can have the rack unloaded, via a hood. The hood here can be pushed vertically upward via a handle.

Such hood-type dishwashers are designed to clean large quantities of washware in the shortest time possible. Thus, in the case of a hood-type dishwasher manufactured by Hobart, the duration of the pre-set standard program which is usually used for normally soiled washware such as plates, bowls, cups and glasses is only approximately 70 seconds, that is to say the theoretical capacity is up to 52 racks per hour.

Almost without exception, commercial dishwashers are fitted with rotating wash and rinse systems. A wash and rinse system usually comprises a washing arm and a rinsing arm. A commercial dishwasher of the type in question here usually has an upper wash and rinse system and a lower wash and rinse system.

During operation, a pump helps to feed the wash water from the wash tank, via a pipeline system, to the washing arms. The washware which is to be cleaned is subjected to the action of the wash water via the washing arms. In the process, the dirt is detached from the washware and introduced into the wash water. The wash water then flows into the wash tank of the dishwasher via a screening system, which holds back coarse residues of dirt.

However, as things stand at the moment, the screening system is not capable of removing all the particles of dirt from the wash water. Depending on their size, the particles of dirt are able to pass through the screening system. These are then pumped via the washing arms again and again by the wash pump. This allows these particles of dirt to distribute themselves, and settle, in the interior of the machine.

For this reason, the person using the dishwasher has the task of cleaning the dishwasher at the end of the shift. For this purpose, removable components can be removed from the dishwasher and cleaned manually in a sink. Furthermore, a lot of effort is required to clean the interior of the machine manually. For this purpose, the user usually cleans the interior with a sponge. A brush is used, in addition, for stubborn soiling.

Laboratory tests showed that many residues of dirt in the form of small particles settle, in particular, in undercuts, and in corners and edges, and these are also very difficult to clean manually.

In particular, the undercuts are to be found on the rear wall of the machine. In the case of conventional, prior-art dishwashers, two parallel hood-guide rails run in a vertical direction on the rear wall of the machine.

In this context, reference is made to the illustration in FIG. 1, which shows the front view of the rear wall 4 of a prior-art dishwasher 1. The rear wall 4 of the machine has two lateral guide rails 5 (on the left-hand side and right-hand side), and the hood 2 is guided in said guide rails.

FIG. 2 shows a side view of the prior-art dishwasher 1.

FIG. 3 shows a detail-specific view of the hood guide which is used for the prior-art dishwasher 1 according to FIG. 1.

Accordingly, the hood guide has hood-guide rails 5 on the rear wall 4 of the machine. These hood-guide rails 5 are made usually in the form of a C profile. A running roller is located at the upper end of the guide rail 5.

The counterpart of the guide rail 5 is located on the hood 2 itself. Here too, there are two parallel, vertically running guide rails. These guide rails are likewise manufactured in the form of a C profile. A running roller is likewise located, on either side, at the lower end of the guide rails.

The running rollers support, and guide, the hood 2 in the guide rails. The running rollers have an encircling groove, wherein a lug of the C profile runs in the groove. This makes it possible to dissipate any side forces which occur and to prevent displacement of the hood.

An exemplary embodiment of the dishwasher 1 according to the invention (in this case: a hood-type dishwasher) will be described in more detail hereinbelow with reference to the illustrations in FIG. 4 to FIG. 9. In the case of this hood-type dishwasher 1, in particular the problem on which the invention is based, that is to say the problem where the hood guides which are used for conventional dishwashers are not easy to access, it also being the case that residues of dirt remain behind on the additional edges of the hood guide during operation of the dishwasher, is solved in that the rear wall 4 of the hood-type dishwasher 1 no longer has to be cleaned manually with a lot of effort being required and in places which are difficult to access; rather, the dishwasher 1 has a flat rear wall 4, which no longer has a hood guide which is visible to staff, as a result of which the rear wall 4 of the machine can be straightforwardly wiped off.

In this way, the manual cleaning outlay for the rear wall 4 of the machine can be reduced to a minimum, and at the same time, during operation of the dishwasher 1, the quantity of adhering residues of dirt is reduced to a minimum. Furthermore, the risk of injury to staff is minimized by getting rid of sheet-metal profiles.

Specifically, the dishwasher 1 according to the invention, which is shown with reference to an exemplary embodiment in FIG. 4 to FIG. 9, is distinguished in that the hood 2 of the dishwasher 1 is assigned at least one guide system for guiding the hood 2 as it moves relative to the machine frame of the dishwasher 1 and, in particular, relative to the rear-side wall region 4, wherein this guide system is of concealed design such that—at least in the open state of the treatment chamber—it is present in its entirety outside the region which, in the closed state of the treatment chamber, is defined by the inner surfaces of the hood 2 and the in particular rear-side wall region 4.

In particular, the exemplary embodiment of the hood-type dishwasher 1 according to the invention makes use of two in particular lateral guide systems or guide rails 5, which—in respect of the guide direction—are arranged in a parallel state, in order for it to be possible to ensure that the hood 2 moves as uniformly and steadily as possible.

In particular, the dishwasher 1 no longer—as has been the case hitherto—has a hood guide which runs on both sides over the entire height of the rear wall 4 of the machine; rather, it just has a guide in the upper region of the rear wall of the machine. In FIG. 4, the position of the hood guide is indicated by an “X”.

As a result, the hood guide is no longer situated in a location which staff can see and clean.

In particular, the new positioning and design of the guide system gives rise to a flat and planar rear wall 4 of the machine. Said rear wall can be cleaned in a considerably more time-saving manner, since fewer residues of dirt adhere to it and the accessibility is significantly improved. However, the existing dimensions and the functions of the hood-type dishwasher 1 remain unchanged.

In the case of the embodiment of the dishwasher 1 according to the invention which is illustrated in the drawings, the hood 2 is also guided via running rollers. For this purpose, said running rollers are nevertheless fitted in the upper region of the machine 1, as indicated in FIG. 4 by the “X”.

Overall, at least two, ideally three, running rollers 6 are installed on each side. As shown in FIG. 9, the positioning of the running rollers 6 is selected such that, when the hood 2 is open, the staff cannot see them. All that staff can see is a flat rear wall 4 of the machine, which is totally free of undercuts and edges.

In particular, the solution according to the invention has no running roller 6 on the hood 2 itself. The hood 2 has only a guide rail 5 for example in the form of a C profile, which is fastened on both sides of the hood 2.

A preferably spring-loaded mechanism, which assists staff in opening and closing the hood 2, subjects the hood 2 to a torque, which causes the hood to tilt rearward. As a result of a central running roller 6 being offset to the rear, the torque is cushioned and the hood 2 can be guided vertically.

In this context, reference is made to the illustration in FIG. 7, which shows, schematically, an isometric view of an upper region of the rear wall 4 of the dishwasher 1 according to the invention.

FIG. 8 shows, schematically, an isometric view of the guide rail 5 on the hood 2 of the dishwasher 1 according to the invention, whereas FIG. 9 shows a side view of the detailed positioning of the running rollers 6 of the guide system of the dishwasher according to the invention.

It can be seen from FIG. 9 that the central running roller 6 is offset a few millimeters to the rear.

Rather than being restricted to the dishwasher 1 which is shown in FIG. 4 to FIG. 9, the invention can be gathered from looking together at all the features disclosed here.

In particular, in this context, it is conceivable for the hood to be guided not just via running rollers 6, but, for example, via roller bearings and/or sliding-friction elements.

According to developments of the dishwasher 1 according to the invention, provision is made for the wash tank of the dishwasher 1 to be designed, and arranged, in relation to the treatment chamber of the dishwasher such that, when wash liquid and/or final rinse liquid are/is being sprayed in the treatment chamber during operation of the dishwasher, at least some of the liquid sprayed flows back into the wash tank under the action of gravitational force, wherein the in particular rear-side wall region merges continuously into a wall region and/or base region of the wash tank. 

What is claimed is: 1-12. (canceled)
 13. A box-type commercial dishwasher (1), comprising a treatment chamber, in which washware accommodated in racks can be treated in accordance with a predefined or predefinable treatment program, wherein the treatment chamber can be closed by a hood (2), which can be moved in the vertical direction relative to a machine frame of the dishwasher (1), wherein, in the closed state of the treatment chamber, the treatment chamber is completely delimited by inner surfaces of the hood (2) and/or additionally by at least one rear side wall region (4), which is fixed to the machine frame of the dishwasher (1), wherein the hood (2) is assigned at least one guide system for guiding the hood (2) as it moves relative to the machine frame and the in particular rear side wall region (4), wherein the at least one guide system is of concealed design such that the at least one guide system is present outside the rear-side wall region (4).
 14. The dishwasher (1) as claimed in claim 13, wherein the at least one guide system comprises at least two lateral guide systems, which, in respect of a guide direction, are arranged in a parallel state.
 15. The dishwasher (1) as claimed in claim 13, wherein the at least one guide system has at least one guide element (6) and at least one guide rail (5), which interacts with the at least one guide element (6), wherein the at least one guide element (6) is connected to the rear side wall region (4) and the at least one guide rail (5) is connected to an inner surface of the hood (2).
 16. The dishwasher (1) as claimed in claim 15, wherein the at least one guide element (6) is provided in a region which, in the open state of the treatment chamber, is present between the rear side wall region (4) and the inner surface of the hood (2), to which the at least one guide rail (5) is connected.
 17. The dishwasher (1) as claimed in claim 16, wherein the at least one guide element (6) is designed in the form of a guide roller, or in the form of a sliding block.
 18. The dishwasher (1) as claimed in claim 15, wherein the guide system has at least two guide elements (6), which are arranged one behind the other in a guide direction.
 19. The dishwasher (1) as claimed in claim 15, wherein the hood (2) is designed in the form of a hood (2) which can be moved vertically relative to the machine frame and relative to the rear side wall region (4), and wherein the at least one guide rail (5) is designed in the form of a vertically running guide rail (5).
 20. The dishwasher (1) as claimed in claim 19, wherein the at least one guide rail (5) has a cross sectional geometry which complements the at least one guide element (6.
 21. The dishwasher (1) as claimed in claim 13, wherein the rear side wall region (4), which delimits the treatment chamber in the closed state, has an undercut free and/or edge free surface.
 22. The dishwasher (1) as claimed in claim 13, wherein, with the exception of a central region of the rear-side wall region, the rear-side wall region (4), which delimits the treatment chamber in the closed state, has an undercut-free and/or edge-free surface.
 23. The dishwasher (1) as claimed in claim 13, wherein the dishwasher (1) has a wash tank, which is designed, and arranged, in relation to the treatment chamber of the dishwasher (1) such that, when wash liquid and/or final rinse liquid are/is being sprayed in the treatment chamber, at least some of the liquid sprayed flows back into the wash tank under the action of gravitational force, wherein the rear side wall region (4) merges continuously into a wall region and/or base region of the wash tank.
 24. The dishwasher (1) as claimed in claim 13, wherein, in the closed state of the treatment chamber, the treatment chamber is delimited laterally by the rear side wall region (4), by a first inner surface of the hood (2), said first inner surface of the hood running parallel to the rear side wall region (4), and by two parallel inner surfaces of the hood (2), said parallel inner surfaces of the hood each being adjacent to the first inner surface of the hood (2). 